In 2G and 3G wireless communication networks of today, such as in GSM (Global System for Mobile telephony, GPRS (General Packet Radio Service), WCDMA (Wideband Carrier Division Multiple Access), CDMA 2000 (Carrier Division Multiple Access) networks, each service based or Radio Access Bearer (RAB) based procedure from the Core Network (CN) is mapped to one or more specific Channel or Radio Bearer (RB) procedures over the air interface.
For example, in WCDMA systems the RAB Assignment procedure from the CN according to the RANAP (Radio Access Network Access Protocol) can be mapped to the RB Setup (due to RAB Setup-Establishment), and/or RB Release (due to RAB Release) and/or RB Reconfiguration (due to RAB Establishment or Release or RAB Modification) procedures in the RRC (Radio Resource Control) protocol towards UE (as Layer 3—L3 specification). Here, by layer 3 the network layer according to the OSI model is meant.
RAB assignment is done similarly in GPRS/EDGE (GPRS/Enhanced Data rates for Global Evolution) networks where there are few different layer-3-procedures, such as ADDITIONAL ASSIGNMENT (to add an additional dedicated channel), ASSIGNMENT COMMAND or CHANNEL MODE MODIFY (to modify existing dedicated channels), CHANNEL RELEASE (to release dedicated channels).
This means today a mobile terminal (UE) has to pass through a set of functions (establishment, release and reconfiguration of RBs) that are usually requested by one CN procedure as e.g. a RANAP RAB Assignment for WCDMA/HSPA (WCDMA/High-Speed Packet Access) networks. Each function presents a separate L3-message in radio control signaling, as it is done according to the RRC protocol. In most cases the separate L3 messages that handle RBs are actually separate procedures for the RAN (such as RAB Establishment with RB SETUP, RAB Release with RB RELEASE, RAB Modification—RB RECONFIGURATION). The signaling between the UTRAN and the UE in this case is illustrated in FIGS. 1-3.
The above mentioned radio functions or procedures are described in detail in 3GPP TS as 25.331 (RRC for WCDMA) or 04.18 (RRC for GSM/EDGE). Analogous or similar examples can be found in other existing mobile systems at the radio level, regardless whether they are 2G or 3G wireless communication network and also in new radio access technologies as LTE (Long Term Evolution), eHSPA (enhanced High Speed Packet Access), and some proposals for wireless communication networks of the fourth generation, i.e. 4G.
Even in the new systems, such as LTE, separate procedures for bearer handling are created via the application protocol between the CN and the RAN. Whereas separate messages are created for bearer setup, release and modification in the form of SAE BEARER SETUP, SAE BEARER RELEASE and SAE BEARER MODIFY in the S1AP (S1 Application Protocol), only one message or procedure RAB ASSIGNMENT REQUEST that is responsible for RABs setup, modify or release is used via RANAP in UTRAN, where RANAP is also an application protocol between CN and RAN.
In today's wireless communication networks where multiple APNs (Access Point Nodes) and multiple PDP contexts are active at the same time between the UE, the radio access part of the wireless communication network and CN, demands on the RAN to handle more than one RAB at the same time are rising. Especially by using so called “All IP”—solutions, multimedia services and IMS roadmaps, it is more likely for application clients in UEs and the service layer in CN to handle multiple RABs.
In these cases solutions provided by known technology may not give necessary flexibilities from the CN and RAN point of view.
In particular, the disadvantages of the solution according to known technology using “one procedure/function per radio control message” create on the one hand more signaling and increased node and UE processing over the CN-RAN (Iu) and the radio (Uu) interface). More specifically, in one solution for the UMTS wireless communication network, one CN requested procedure is handled as several RRC functions called RAN procedures and several RRC messages are sent towards UE.
On the other hand, this solution also leads to worse performance in the form of a longer setup, release and modify procedure and increases the delay before a RAB is established. As a consequence, a greater amount of messages over radio interfaces may lead to worse KPIs (Key Performance Indices) and therefore greater risk for the occurrence of Rice conditions or exceptional cases. By “Rice conditions” such conditions are meant where in a scenario where parallel request messages are transmitted from the RAN to one UE, the RAN may receive a response message to the second request before receiving the response message to the first request.
Even with new radio access technologies offering high throughput, such as LTE or eHSPA there are areas where the RAN performance can be improved.
These and other needs in known technology are addressed by the present invention.